1. Field of the Invention
This invention relates to an apparatus for recording an image on a photosensitive recording medium.
2. Description of Related Art
Conventionally, when an image recording apparatus, such as a color photocopier, copies an original, rays are irradiated onto and reflected by the original, thereby resulting in the formation of an image. Specifically, when the photosensitive recording medium, such as a photosensitive sheet, is exposed to the rays reflected by the original, a latent image corresponding to the image on the original is formed on the surface of the photosensitive recording medium. Subsequently, the surface of the photosensitive recording medium with the latent image formed thereon is put in contact under pressure with the developer applied surface of a developer sheet, and the image is transferred from the photosensitive recording medium onto the developer sheet. By heating the developer sheet, a chromatic image, corresponding to the latent image, is developed on the developer sheet.
When the component colors of the chromatic image on the original are similar to each other in pigment and brightness, for example, when the original bears the scenery of the sea mainly composed of blue, the related-art image recording apparatus obtains an output chromatic image having poor color gradation. The optimum conditions of the exposure of the original to the rays vary with the hue and brightness of the rays. Consequently, some hue characteristics of the original result in an output chromatic image of undesirable quality with poor color gradation.
The optimum conditions of the exposure of the original to the rays also vary with the brightness characteristics of the original, such as the average brightness and contrast of the original. Some brightness characteristics of the original result in an output chromatic image of undesirable quality with poor color gradation. For example, when the quantity of the rays reflected by the original is large, when the original has low brightness and when the original is inclined to white, the output chromatic image has no distinctive color gradation, even if the quantity of the reflected rays is varied. As a result, the output chromatic image becomes uniformly light and has no distinctive color gradation. The same problem arises when the original has dark color.